We need a means to automate upgrading the Connectcore 6UL module firmware to our custom firmware images (u-boot, Linux, rootfs) during first boot in manufacturing testjig.

One approache would be to:
1. Connect console to testjig computer and monitor console output during startup.
2. Write a program that parses the console output from u boot and sends a character to stop the boot.
3. Then automate the commands neccesary to update via TFTP.

Any other good approaches to enable automatic update of firmware?
Or
Anyone already done this that can share their solution?